checkpatch: get default codespell dictionary path from package location

The standard location of dictionary.txt is under codespell's package, on
my machine atm (codespell 2.1, Artix Linux):
/usr/lib/python3.9/site-packages/codespell_lib/data/dictionary.txt

Since we enable the codespell by default for SOF I have constant:
No codespell typos will be found - \
file '/usr/share/codespell/dictionary.txt': No such file or directory

The patch proposes to try to fix up the path following the recommendation
found here:
codespell-project/codespell#1540

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>

scripts/checkpatch.pl

@@ -73,6 +73,12 @@
 my $tabsize = 8;
 my ${CONFIG_} = "CONFIG_";
 
+# Override the codespellfile location based on codespell install location
+if (which("codespell") ne "" && which("python") ne "") {
+	my $codespell_dict = `python -c "import os.path as op; import codespell_lib; print(op.join(op.dirname(codespell_lib.__file__), 'data', 'dictionary.txt'), end='')" 2> /dev/null`;
+	$codespellfile = $codespell_dict if (-e $codespell_dict);
+}
+
 sub help {
 	my ($exitcode) = @_;
 
@@ -130,7 +136,7 @@ sub help {
   --ignore-perl-version      override checking of perl version.  expect
                              runtime errors.
   --codespell                Use the codespell dictionary for spelling/typos
-                             (default:/usr/share/codespell/dictionary.txt)
+                             (default:$codespellfile)
   --codespellfile            Use this codespell dictionary
   --typedefsfile             Read additional types from this file
   --color[=WHEN]             Use colors 'always', 'never', or only when output